package com.yb.nowcoder;

import java.util.Scanner;

/**
 * 华为机试练习棋盘
 */
public class Main11 {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while (in.hasNextInt()) {
            int n = in.nextInt();
            int m = in.nextInt();
            System.out.println(f(n, m));
        }
    }

    public static int f(int n, int m) {
        if (n == 0 || m == 0) return 1;
        return f(n - 1, m) + f(n, m - 1);
    }
}
